The present invention relates to a data storage tape cartridge. More particularly, it relates to a data storage tape cartridge configured to support a tape reel assembly in a center position relative to an opening formed by a housing when the tape reel assembly is in a locked state.
Data storage tape cartridges have been used for decades in the computer, audio, and video fields. The data storage tape cartridge continues to be an extremely popular form of recording large volumes of information for subsequent retrieval and use.
A data storage tape cartridge generally consists of an outer shell or housing maintaining at least one tape reel assembly and a length of magnetic storage tape. The storage tape is wrapped about a hub portion of the tape reel assembly and is driven through a defined tape path by a driving system. The housing normally includes a separate cover and base, the combination of which forms an opening (or window) at a forward portion thereof for allowing access to the storage tape by a read/write head upon insertion of the data storage tape cartridge into a tape drive. This interaction between storage tape and head may take place within the housing (for example, with a mid-tape load design), or the storage tape may be directed away from the housing to an adjacent area at which the read/write head is located (for example, with a helical drive design or a leader block design). Where the tape cartridge/drive system is designed to direct the storage tape away from the housing, a single tape reel assembly is normally employed. Conversely, where the tape cartridge/drive system is configured to provide head/storage tape interaction within or very near the housing, a two- or dual-tape reel assembly configuration is typically utilized.
Regardless of the number of tape reel assemblies associated with a particular data storage tape cartridge, the tape reel assembly itself is generally comprised of three basic components; namely, an upper flange, a lower flange, and a hub body. The hub body forms an outer, tape-winding surface about which the storage tape is wound. The flanges are disposed at opposite ends of the hub, and are spaced to approximate the height of storage tape. Finally, the tape reel assembly forms drive teeth that are engaged by corresponding teeth of a drive chuck for rotating the tape reel assembly upon insertion into a tape drive.
Upon final assembly, the tape reel assembly is generally aligned with a circular tape reel opening formed through the housing (typically in the base section). This tape reel opening is sized to allow interaction between the tape drive chuck and the drive teeth associated with the tape reel assembly. When the data storage tape cartridge is not in use, the tape reel assembly is typically xe2x80x9clockedxe2x80x9d or otherwise prevented from undesirably rotating. To this end, a brake assembly is provided for each tape reel assembly. The brake assembly can assume a wide variety of forms, such as multiple brake bodies biased to selectively engage an outer circumference of the tape reel assembly. A more common, less expensive approach includes a single brake body and a spring disposed within a central bore of the tape reel assembly. The brake body is slidably associated with a protrusion or post formed by the housing cover opposite the tape reel opening. Further, the spring biases the brake body into engagement with the tape reel assembly, such that the brake body rigidly connects the tape reel assembly with the cover via the post. For example, the brake body can form a toothed surface configured to engage interior brake teeth formed by the tape reel assembly. In this locked position, then, the tape reel assembly is xe2x80x9clockedxe2x80x9d to the housing cover, and thus will not rotate.
The above-described brake assembly has proven to be highly effective in preventing tape reel rotation when the data storage tape cartridge is not in use. However, the brake assembly only generally aligns the tape reel assembly relative to a center axis of the tape reel opening. Manufacturing tolerances associated with the various cartridge components inherently allows the tape reel assembly to laterally move or shift within the housing. This potential concern is exacerbated when the cartridge is maneuvered from a horizontal orientation. For example, handling and/or storage of the cartridge commonly requires that the cartridge be turned on its side (i.e., vertically oriented). As part of this movement, or when vertically oriented for an extended period of time, the tape reel assembly may laterally move or shift within the housing such that the tape reel assembly is no longer aligned with the tape reel opening. In the event of a relatively substantial lateral shift, the tape drive chuck may experience difficulties in engaging the drive teeth of the tape reel assembly during subsequent use.
More recent data storage tape cartridge designs have attempted to solve the above-described centering concern by forming a chamfered edge in the housing base at the tape reel opening. The bottom flange associated with the tape reel assembly includes an angled protrusion that contacts the chamfered edge in the locked position, in theory centering the tape reel assembly relative to the tape reel opening. Unfortunately, product specifications limit the allowable spring force provided by the brake assembly spring. As such, the angled protrusion associated with the bottom flange readily slides or slips along the chamfered edge. Thus, the tape reel assembly will still transversely or lateral move or shift when the cartridge is vertically oriented.
Data storage tape cartridges are important tools used to maintain vast amounts of information. As the cartridge and drive components continue to evolve, alignment deviations, such as alignment of the tape reel assembly relative to the tape reel opening in the housing, are less tolerable. Therefore, a need exists for a data storage tape cartridge configured to prevent transverse movement of the tape reel assembly in a locked state.
One aspect of the present invention relates to a data storage tape cartridge including a housing, a tape reel assembly, a brake body, a spring, and a storage tape. The housing includes a base and a cover that combine to define an enclosed space. The base forms a tape reel opening, whereas the cover forms a post opposite the tape reel opening. The tape reel assembly is rotatably disposed within the enclosed space and includes a hub, opposing top and bottom flange components, brake teeth, and an inner surface. The hub defines a tape-winding surface. The opposing upper and lower flange components extend radially from opposite ends of the hub, respectively. The brake teeth extend axially inwardly relative to the upper flange component. Finally, the inner surface is formed by the tape reel assembly and defines an engagement section apart from the brake teeth. The brake body includes a stem, a head, a toothed section, and a centering feature. The stem is configured to be slidably mounted to the post formed by the cover. The head extends axially relative to the stem. The toothed section is formed at a surface of the head opposite the stem. In this regard, the toothed section corresponds with the brake teeth of the tape reel assembly. The centering feature extends radially outwardly from the head and forms a circumferential edge that is radially spaced from the toothed section. The spring is positioned about the post to bias the brake body to a locked state. In the locked state, the toothed section engages the brake teeth to prevent rotation of the tape reel assembly. Further, in the locked state, the circumferential edge of the centering feature contacts the engagement section of the tape reel assembly to support the tape reel assembly in a centered position relative to the tape reel opening. Finally, the storage tape is wound about the tape-winding surface of the hub. With this configuration, interaction between the circumferential edge and the engagement section limits lateral shifting of the tape reel assembly relative to the tape reel opening when the data storage tape cartridge is vertically oriented.
Another aspect of the present invention relates to a brake body for use with the data storage tape cartridge to selectively maintain a tape reel assembly in a locked state. The brake body comprises a stem, a head, a circular ring of teeth, and a flange. The stem forms a passage for slidably mounting to a post. The stem terminates in a trailing end. The head extends in an axial fashion opposite the trailing end of the stem. In this regard, the head has a diameter greater than an outer dimension of the stem. The circular ring of teeth is formed at an upper surface of the head and define an outer diameter. Finally, the flange extends radially from the head and terminates in a circumferential edge. In this regard, the circumferential edge has a diameter greater than the outer diameter defined by the ring of teeth. In one preferred embodiment, the circumferential edge has a tapered axial extension. With this configuration, the brake body engages a tape reel assembly both at the teeth and the circumferential edge.
Yet another aspect of the present invention relates to a method of supporting a tape reel assembly in a center position relative to a tape reel opening in a housing of a data storage tape cartridge. The method includes providing the tape reel assembly with break teeth and an inner surface with an engagement section apart from the brake teeth. A brake assembly is provided as including a brake body forming a toothed section and a circumferential edge radial spaced from the toothed section. The brake assembly is biased to a locked state in which the toothed section engages the brake teeth to impede rotation of the tape reel assembly and the circumferential edge contacts the engagement section. With this method, upon articulation of the data storage tape cartridge from a horizontal orientation, the brake body prevents lateral displacement of the tape reel assembly relative to the tape reel opening in the locked state via contact between the circumferential edge and the engagement section.